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Glenn C. Wright

Two lemon [Citrus limon (L.) Burm.] cultivar selection trials are being conducted at the Yuma Mesa Agriculture Center in Somerton, Ariz. Some selections in these trials include: `Allen Eureka', `Berna', `Cook Eureka', `Cascade Eureka', `Cavers Lisbon', `Strong Lisbon', `Femminello Comune', `Lapithkiotiki', `Limoneira 8A Lisbon', `Limonero Fino 49', `Monroe Lisbon', `Primofiori', `Santa Teresa', `Walker Lisbon', and `Villafranca'. Selections that have had superior yields include `Cascade Eureka', `Cook Eureka', `Strong Lisbon', `Limoneira 8A Lisbon', `Limonero Fino 49', `Primofiori', `Femminello Comune', and `Villafranca'. Fruit size data suggest that `Limonero Fino 49' has consistently good fruit size, and consistently larger fruit than `Limoneira 8A', the industry standard. `Cavers Lisbon' and `Femminello Comune' also have good fruit size. `Lapithkiotiki' also had large fruit size, but its shape was unacceptably elongated. We also found significant differences in peel thickness and juice pH among the selections. `Santa Teresa' had significantly lower juice pH and a thinner peel than some of the other selections under evaluation.

Open access

Maegen Lewis, Melanie Stock, Brent Black, Dan Drost, and Xin Dai

are critical for optimizing cut flower production against regional constraints ( Ortiz et al., 2012 ; Wien, 2009 ). Surveys of growers emphasize this need with season extension, control of bloom timing, and cultivar selection as the top

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Hardeep Singh, Bruce Dunn, Mark Payton, and Lynn Brandenberger

cultivar ranking from the data derived from field experiments cannot be applied directly to cultivar selection for hydroponics ( Molders et al., 2012 ). Vital and Teixeira (2002) evaluated different lettuce cultivars (Cinderella, Monica, Elizabeth, and

Open access

Joara Secchi Candian, Timothy Coolong, Bhabesh Dutta, Rajagopalbabu Srinivasan, Alton Sparks, Apurba Barman, and Andre Luiz Biscaia Ribeiro da Silva

), zucchini, and yellow squash ( Anwar et al., 2018 ; Wraight et al., 2000 ). The aforementioned studies reported that cultivar selection is a key step in the implementation of an integrated pest management strategy for sweetpotato whitefly populations and

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Kristine M. Lang, Ajay Nair, and Kenneth J. Moore

, fertility management, and cultivar selection, which can be more cost-effective alternatives to shadecloth application. In general, the cultivar Sirius had a high incidence of BER, which may be a consideration for growers who have previously struggled with

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Ted E. Bilderback and Paul R. Fantz

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Md J. Meagy, Touria E. Eaton, and Allen V. Barker

Calcium-rich vegetables in the diet could ameliorate the potential for calcium (Ca) deficiency in human nutrition. This study investigated the prospect of increasing Ca density of lettuce (Lactuca sativa L.) through cultivar selection and nutrient management in a greenhouse. Eighteen lettuce cultivars including butterhead, romaine, and loose-leaf phenotypes of heritage and modern genetics were tested. Organic fertilizer (3N–0.7P–3.3K) and commercial conventional fertilizer (20N–4.4P–16.6K) factored with three Ca levels (50, 100, 200 mg·L−1 as CaCl2) were the fertilizer regimes. Calcium in whole shoots was analyzed by atomic absorption spectrometry of oven-ashed samples. Heritage cultivars had a significantly higher Ca concentration (1.93% dry weight) than modern cultivars (1.54%). Loose-leaf phenotypes had the highest Ca concentration (2.06%) followed by butterhead (1.66%) and romaine (1.49%). Accumulation of Ca was higher with the conventional fertilizer (1.90%) than with the organic fertilizer (1.58%). Elevated Ca level in the fertility regimes raised the Ca concentration in lettuce from 1.56% at 50 mg·L–1 to a mean of 1.82% at 100 mg·L−1 and 200 mg·L−1. Large differences in Ca concentration occurred among individual cultivars with ranges from 1.27% to 3.05%. ‘Salad Bowl’, ‘Red Deer Tongue’, ‘Buttercrunch’, and ‘Bronze Mignonette’ were the top in cultivar ranking with mean Ca concentration of 2.50%, whereas ‘Adriana’, ‘Australe’, ‘Coastal Star’, and ‘Forellenschluss’ were low accumulators with a mean of 1.33%. Head size of cultivars had no correlation with Ca concentration. This experiment indicates that selection of nutrient regimes and cultivars can be used to increase Ca accumulation in lettuce.

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Ninghang Wang, Chao Zhang, Sainan Bian, Pengjie Chang, Lingjuan Xuan, Lijie Fan, Qin Yu, Zhigao Liu, Cuihua Gu, Shouzhou Zhang, Yaling Wang, and Yamei Shen

Magnolia (Magnoliaceae) is widely cultivated for its beauty; however, despite this, the components of the different flower colors in Magnolia have not been elucidated. In this study, the color parameters of 10 Magnolia petals with different colors were measured by the Royal Horticultural Society Color Chart (RHSCC) and a color reader CR-10. The composition and content of the flavonoids in the petals were analyzed by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) as well as HPLC with electrospray ionization and mass spectrometry (HPLC-ESI-MS2). All results showed that the 10 petals were divided into four color groups. Regarding the flavonoid composition, four types of anthocyanins, including Cyanidin-glucosyl-rhamnoside (Cy-GR), Cyanidin-glucosyl-rhamnosyl-glucoside (Cy-GRG), Peonidin-glucosyl-rhamnoside (Pn-GR), and Peonidin-glucosyl-rhamnosyl-glucoside (Pn-GRG), were identified, as well as 10 types of flavonols. The flavonols included isorhamnetin, quercetin, kaempferol, and their glycosides, which included rutinoside, rhamnose, and glucoside. Cyanidin and peonidin make Magnolia petals appear red-purple and purple, respectively, and the flavonols perform as evident auxiliary pigments, particularly quercetin. The Magnolia cultivar flower phenotypes sampled in this study differed by changes in their existing flavonoid content rather than by the appearance of new flavonoids. Consequently, this study provides a reference for further revealing the basis of Magnolia flower color and provides clues for color breeding.

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Kuen-Woo Park and Min-Jea Kim

This experiment was carried out to select resistant cultivar to CMV in cucumber using Elisa-test and protoplast isolation method. Twenty domestic cultivars or lines and 8 European cultivars were ested for resistance by Elisa test. Among the domestic cultivars, DADAKI group was found to be susceptible and CHEONGJANG group resistant. Among all the cultivars and lines tested, a European cultivar, DALIBOR and Janghyungheukjinju Korean line were found to be highly resistant. When comparing for the protoplast yield depending upon the positions of seedlings (cotyledon, young leaf and hypocotyl), the highest protoplast yield could be obtained from cotyledons in macerozyme 0.5% + cellulose 2.0%. Protoplast yields in susceptible cultivars were higher than those from resistant cultivars. Differences in cell wall thickness between susceptible and resistant cultivars were observed.

Open access

Andre Luiz Biscaia Ribeiro da Silva, Joara Secchi Candian, Lincoln Zotarelli, Timothy Coolong, and Christian Christensen

Soil nitrogen (N) is easily leached in cabbage (Brassica oleracea var. capitata) production areas of southeastern United States characterized by sandy soils with low water-holding capacity. Soil N leaching in these areas is increased after rainfall events; consequently, growers increase the fertilizer N application to protect against N deficiencies and yield loss. The objective of this study was to evaluate the effects of three fertilizer N rates on yield and head quality for common cabbage cultivars used by Florida and Georgia growers during four cabbage growing seasons. Field experiments were conducted in Hastings, FL, in 2016 and 2017, and in Tifton, GA, in 2018 and 2019. A randomized complete block design was used with a split-plot design of fertilizer N rate and cabbage cultivar. Fertilizer N rate treatments consisted of the application of 170, 225, and 280 lb/acre N and were assigned as the main plot. Cabbage cultivars Bravo, Bronco, Bruno, Capture, Cheers, and Ramada were assigned as the sub-plots. Weather conditions were monitored during all growing seasons, and total, marketable, and unmarketable yields, as well as cabbage head polar and equatorial diameters, and core height and width were measured. In Florida, there was a significant interaction for growing season and fertilizer N rate. The Florida 2016 cabbage season experienced 10.5 inches of rainfall, and fertilizer N rates had no effect on cabbage yields. Total and marketable yield averaged 45,391 and 38,618 lb/acre among fertilizer N rates in 2016, respectively. Rainfall accumulated 2.1 inches during the 2017 study in Florida, which was less than the crop evapotranspiration. In response, total and marketable yield were higher for the applications of 225 lb/acre N (51,865 and 49,335 lb/acre, respectively) and 280 lb/acre N (54,564 and 52,219 lb/acre, respectively) compared with the application of 170 lb/acre N (47,929 and 43,710 lb/acre, respectively). In Georgia, there were no significant interactions between production season and fertilizer N rates. In addition, there were no significant main effects of season or fertilizer N rate. Rainfall events accumulated 20.9 and 7.8 inches during the 2018 and 2019 growing seasons, respectively. Total and marketable yields averaged 37,290 and 33,355 lb/acre, respectively for the two growing seasons in Georgia. Cabbage cultivar had no interaction with fertilizer N rate in any location. ‘Cheers’ (52,706 lb/acre) had the highest total yield in Florida, and ‘Ramada’ (38,462 lb/acre) and ‘Bronco’ (39,379 lb/acre) had the highest total yields in Georgia. In conclusion, the application of 225 lb/acre N was sufficient to sustain cabbage yields, but yields of the 170- and 225-lb/acre N treatments were not different when rainfall events exceeded crop evapotranspiration.